# Concepts

* [Stoicism](stoicism.md) - The Hellenistic school of philosophy founded in Athens by Zeno of Citium, treated across this library as both a theoretical system (logic, physics, ethics) and a practical discipline of virtue, fate, and what is within one's control.
* [Philosophy](philosophy.md) - The broader discipline of which Stoicism is one school; in the Hays introduction, traced largely to the fifth-century BC Athenian thinker Socrates.
* [Logos](logos.md) - In Stoicism, the all-pervading rational principle that orders and directs the universe—synonymous with nature, Providence, or God—and present in each person as the faculty of reason.
* [Dichotomy of control](dichotomy-of-control.md) - Epictetus's foundational distinction, opening the Enchiridion: some things are within our power (judgement, impulse, desire, aversion) and some are not (the body, property, reputation, office).
* [The three disciplines](three-disciplines.md) - The framework in the Hays introduction (and Meditations 7.54): the disciplines of perception, action, and will—seeing objectively, acting justly, and accepting what is outside our control.
* [The four cardinal virtues](four-cardinal-virtues.md) - The Stoic virtues Marcus highlights (Meditations 3.6): wisdom, justice, courage, and self-control (temperance), held as the highest goods.
* [Amor fati](amor-fati.md) - The acceptance and love of one's fate, aligned with the Stoic discipline of will and willing acquiescence to whatever the logos has ordained.
* [Memento mori](memento-mori.md) - Remembrance of death as a guide to action, as in Marcus's 'You could leave life right now—let that determine what you do and say and think' (Meditations 2.11).
* [Providence](providence.md) - The Stoic conviction that the universe is benevolently ordered by the logos, contrasted in the Hays introduction with the random Epicurean universe.
* [Tranquility, fearlessness and freedom](stockdale-triad.md) - Stockdale's distilled Stoic triad—tranquility, fearlessness, and freedom—achieved by mastering one's moral purpose and accepting what lies outside one's control.